Paradigm Elite in-ceiling speakers with angle baffles are excellent and I use them in my family room w great success.
They cost $650 or $750 each depending on the model. So for four speakers that would be $2600 or $3000 for a set four. I would never put that kind of cash into ceiling speakers. In addition they do not have a back box. So I could not even install them in this room without making them. For reasons of fire code and just fire safety I have come to the conclusion no speakers should be in wall or in ceiling without back boxes and fire codes should be followed. I know that if I had put those in during construction I would not have been granted a certificate of occupancy by the city of Eagan. They went over my center through wall installation with a fine tooth comb, and I had to go to great lengths to satisfy them.
My downstairs in wall speakers are all enclosed, and not only that, they are in a "false wall", with the fire wall and barrier behind the installation.
I have thought for some time in home audio, HT and yes, this forum, we have run roughshod of best practice and safety in terms of fire codes.
In any event as I have said, those speakers I installed do just the job I want. They produce a very realistic ambient field and are quite good enough for Hollywood's effects.
Talking of which I note they mix in way that they seem scared to send much power to speakers other then the front stage and sub. I think they are scared of getting complaints of blown speakers. I have really good and competent surrounds and rear backs, but they rarely get driven. In fact the only one that does really drive them is the Laplander circular drumming in the first movement of Aho's first symphony. That puts heavy demands all round the system. Yet, the reviews all panned the disc as unplayable. Well it is playable here and really impressive.